NAS (network-attached storage) is getting more and more popular these days. As with other types of data storage, such as your computer’s local storage, external storage and cloud storage, there can be duplicate files on your NAS drives. You may want to find and delete unwanted duplicates to free up storage space and better manage your files.
Synology is a well-known name in the world of NAS. In this article, I’ll discuss how to use a Synology duplicate file finder to find and delete duplicate files on Synology drives.
The good news is that Synology NAS itself provides a way to help users identify duplicate files. Here are four facts about this native duplicate file finder for Synology NAS.
How to access it
You can make your Synology NAS more powerful by installing tools known as packages. The Storage Analyzer package is one of them. With Storage Analyzer, you can perform various tasks, including identifying duplicate files on your Synology NAS.
How to find duplicates
Storage Analyzer can identify “potential duplicate files” and provides two options to configure the identification: “Ignore file names” and “Ignore modification time”.
By “potential”, Storage Analyzer means that it doesn’t compare full hash values, because full comparison can take time. Storage Analyzer seeks a balance between accuracy and speed. If you need a more accurate duplicate file finder that compares full hash values, you can go to this part of the article.
How many duplicates can be found
You can specify the maximum number of duplicate files to be found. For example, if there are 1000 duplicate files on your NAS and you set the max number to be 500, Storage Analyzer will stop finding once it has found 500 duplicates.
How to delete duplicates
In each set of duplicate files, you need to manually delete the redundant one(s), which can take a while. If you prefer bulk deletion, you can check out the third-party solution that provides auto selection and preset selection rules. For example, the By Priority rule allows you to choose which duplicates to keep based on their locations, keeping files from your chosen folder and removing others.
1. In Synology DiskStation Manager, open Package Center.
2. Search for and install Storage Analyzer. Open it.
3. Choose Create in the Report Profile section. Give the task a descriptive name, such as Duplicates. Click Next.
4. In the Select Report Items list, select the Potential Duplicate Files checkbox. Click Next.
5. Select in which folders you want to find duplicate files. Click Next.
6. Configure the identification of duplicate files based on your needs. Click Next.
7. In the Summary dialog, select the Generate reports now checkbox. Click Done.
8. When the identification is complete, open the report. In the File section on the left, click Duplicates to view the duplicate files found on your Synology NAS.
9. In each set of duplicates, select the item(s) you want to remove.
10. From the Action dropdown menu, click Delete to delete all selected duplicates at once.
Tip: If you are not sure which files to keep and which to delete, you can start by identifying the source of each file. You can keep the version from the most relevant folder. If certain duplicates are shared with others, you can keep them for continued availability. Generally, you may want to remove all but one item in each set to reclaim storage, but sometimes you may need to keep all items.
There are still other ways to remove duplicate files on Synology NAS.
Available for Windows and Mac, Cisdem Duplicate Finder is an easy-to-use app to find and delete duplicate files. It can detect duplicate images, audio files, videos, documents, archives and other types of duplicate files.
Let’s take a close look at it, learning about its advantages over Storage Analyzer and finding out if it works for you.
Cisdem Duplicate Finder deeply scans within and across specified locations, identifying duplicates by comparing both full hash values and file sizes. This method minimizes the risk of checksum collisions, providing a high level of accuracy. After the scan, it displays all duplicate files for you to preview and automatically selects all but one file for deletion in each set, with options for easy customization (e.g., Select Newest/Oldest or Select by Filename).
It can help users find and delete duplicate files in different locations.
In the same way, if you know how to successfully mount your Synology drive to your computer, you can use Cisdem Duplicate Finder as a duplicate file finder for Synology.
Important: If you are NAS-savvy and know exactly what you are doing, you can try this third-party solution. If the answer is no or you are not sure, then you may ignore this solution.
1. Mount your Synology NAS to your computer.
2. Download and install Cisdem Duplicate Finder.
3. Click the Add button + to select your NAS to scan.
4. Optionally, go to Settings to explore customization options. For example, you can exclude specific files and folders from the scan by specifying locations, file size range, and file extensions.
Also, you can prioritize which duplicates to remove based on their locations.
5. Click Scan. When the scan is done, the results window will display duplicate files for you to view.
6. In each set of duplicate files, all but one is automatically selected for removal. You can manually select/deselect files if needed. Or, choose a selection rule to apply it to the sets you highlighted in the left sidebar.
7. Once all the unwanted duplicates are selected for removal. Click Delete to get rid of them all at once.
Tip: Cisdem Duplicate Finder is an excellent duplicate photo finder, which can identify exactly identical photos (regardless of file names), photos that look the same to the naked eye but have different sizes or formats, and similar-looking photos on Synology NAS. If you only want to view the found exact duplicate photos, you can go to the Images tab of the results window. Non-exact duplicate photos and similar photos are listed under the Similar Images tab.
This article talks about two Synology duplicate file finders and how to use them respectively. One solution is from Synology itself, which is basic and not that customizable and requires you to delete duplicates by hand. The other one is third-party, which can provide higher accuracy and efficiency and may require you to be NAS-savvy. The best choice depends on your needs and preferences.
With a passion for tech and writing, Sarah joined Cisdem, where she focuses on creating articles about using utility tools to enhance file management and simplify contact management.